Recovery after high intensity exercise is becoming increasingly important as sport and exercise become more competitive. After a high-intensity bout of exercise, muscle soreness, including delayed-onset muscle soreness (“DOMS”), decreased power, and decreased performance often follow. DOMS is the muscle soreness that occurs after unaccustomed or high-intensity exercise, most commonly anaerobic (Clarkson & Hubal, 2002). Soreness is usually noted at 24 hours post-exercise and can last any where from five to seven days post-exercise (Clarkson & Hubal, 2002; Feasson et al., 2002; Nosaka & Clarkson, 1996). It has been shown that many high-intensity anaerobic exercises cause DOMS (Lee et al., 2002; McBride et al., 1998; Twist & Eston, 2005). The exact physiological mechanisms responsible for the DOMS resulting from this type of exercise are not agreed upon, though many have been proposed, including changes in osmotic pressure, fluid retention, calcium regulation, and acute inflammation (McArdle, Katch, & Katch, 2001).
Thus there is a need for a supplement that can decrease oxidative stress and inflammation to reduce the magnitude and length of muscle soreness, decreased power and decreased performance so that an athlete may be able to train more frequently, increasing long-term performance. Antioxidant and anti-inflammatory supplements, such as theaflavins found in black tea, have been suggested to decrease oxidative stress and inflammation resulting from physiological stressors such as intense exercise (McKay & Blumberg, 2002; Tomita, Irwin, Xie, & Santoro, 2002) which could help reduce the length and magnitude of post-exercise soreness. This could thus shorten the decrease in strength and performance associated with delayed-onset muscle soreness (DOMS) (Bloomer, Goldfarb, McKenzie, You, & Nguyen, 2004; Clarkson & Thompson, 2000). However, previous research has shown that the effect of anti-inflammatory compounds on DOMS is not currently understood or predictable (Stone et al, 2002; Rice et al, 2008; Dudley, G A, 1999; and McAnulty, et al, 2007)
Catechins, theaflavins and thearubigins are polyphenolic compounds and major components of black tea and oolong tea. Theaflavins and thearubigins are tea-color materials. The approximate mean percentages of these compounds found in black tea beverages are shown in table 1:
TABLE 1Major components of black tea beveragesCatechins 3-10Theaflavins3-6Thearubigins12-18Components measured in wt % of extract solids.Theaflavins are a class of benzo[7]annulenone compounds which are formed from oxidation reactions of polyphenolic compounds. There are 12 components in theaflavins, including theaflavin (TF), theaflavin-3-gallate (TFMG), theaflavin-3,3′-digallate (TFdiG) and theaflavin-3′-gallate (TFM′G), which are depicted by the following formula:
which are the four major components. Pure theaflavins are orange colors, form needle crystals, have melting points of 237-240° C., are soluble in water, methanol, ethanol, acetone, n-butanol and ethyl acetate, are slightly soluble in ethyl ether, and are insoluble in chloroform and benzene. Theaflavins in solution are clear orange in color and are slightly acidic with a pH value of about 5.7. The solution color is not affected by the pH of the tea extraction solution, but theaflavins are auto-oxidative in basic solution. The oxidation process increases with the pH value.
Thearubigins are a class of complex, inhomogeneous brown colored phenolic compounds, with a range of molecular weight of 1,000-40×103. Due to inhomogeneity, unclear structure, and unknown properties, it is difficult to isolate and purify the thearubigins.
Tea polyphenols, including catechins and theaflavins, are known for reducing triglyceride, removing free radicals, having anti-oxidant, anti-bacteria, anti-virus, anti-tumor, anti-mutagenic, and odor removal properties, and treating cardiovascular diseases, etc. They are applied in pharmaceutical, nutraceutical and food additive fields.